岩溶多重介质地下水模拟技术及应用进展

由于岩溶发育的极不均匀性和岩溶含水介质的多重介质性等特征, 使得岩溶水系统的地下水运动规律呈现出复杂多变的特点, 在孔隙或微小裂隙含水介质中岩溶水满足达西流, 而在岩溶管道中可能出现非达西运动, 这给岩溶区地下水模拟带来了极大挑战。系统地梳理了岩溶水流和溶质运移模拟的主要方法, 总结了复杂岩溶多重介质系统地下水模拟技术的现状, 并结合我国南方岩溶和北方岩溶各自的特点, 提出岩溶水模型在实际应用中需要关注的要点。主要包括: 需加强野外调查和观测, 提高模型中对岩溶含水介质结构非均质性表征的精度; 进一步深化对岩溶水运动机理的研究, 刻画岩溶多重介质的水流特征以及水交换机理; 针对北方岩溶水系统模拟, 可选择等效连续多孔介质模型, 重在耦合区域分布的岩溶溶孔－裂隙介质中慢速渗流与脉状分布的强径流带快速流; 对于南方岩溶区, 建议考虑建立分布式流域水文模型与能刻画集中管道流多流态变化的多重介质模型的岩溶地下水耦合模型。 

Overview of groundwater modeling technology and its application in karst areas with multiple-void media

Due to the extremely heterogeneous distribution of karst and the multi-media nature of karst aquifer medium, the groundwater flow in karst water system presents complex and changeable characteristics. It follows Darcy flow law in the pores or fissures, and non-Darcy flow law in the karst pipelines, which brings great challenges to groundwater modeling in karst areas. This paper systematically worked through the main methods of karst water flow and solute transport simulation, summarized the current situation of groundwater simulation technology in complex karst multimedia systems, and pointed out the key issues that should be considered in the practical application of karst water modeling according to the characteristics of karst in south and north China. The main findings include: it is necessary to strengthen field investigations and observations to improve the accuracy of the characterization of the heterogeneity of karst aquifer media in the model. Furthermore, the research on the mechanism of karst water movement should be deepened to depict the flow characteristics and the water exchange mechanism in the karst multimedia. For the simulation of karst water systems in North China, the equivalent continuous porous media model can be selected, focusing on the coupling model of slow seepage in the karst pore fissure media with the rapid flow in the strong runoff zone. For the karst area in South China, it is suggested to consider the establishment of a coupling model between the distributed watershed hydrological model and the multimedia karst groundwater model that can describe the changes in various flow regimes in complex multiple-void media.